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Tuesday, November 20, 2012

Revit 2013/AutoCAD MEP 2013 IFC Improvements

This post is part of an AU class this year, MP1465, Supercharge
Your AutoCAD® MEP 2013. It came up as we started working with outside vendors that are solid AutoCAD MEP users, but not Revit users - and that's what we're using.First up, know the rules:- Architecture and Structure items convert pretty nicely, with ACAD Arch walls converting to Revit walls. You may need to swap some styles, check justifications, etc. but getting the overall model works pretty well.- MEP objects come into Revit from ACAD MEP as in-place families, but if you setup your import options, and have your classification definitions assigned to MEP objects in ACAD MEP, then they come in as "pipes, pipe fittings, duct, etc.". Be aware - they don't have the same behavior as a duct, pipe, etc. that was created with native Revit tools. But you can add connectors as needed to make these types of connections.Here's the excerpt from the class (or as I like to call it, the "tease")...

IFC stands
for Industry Foundation Class, and it’s a file format that is universally
shared between CAD platforms. The intent is that an object in a program like
AutoCAD MEP can be converted into the same type of object in Revit, or other
BIM applications.

In order for an object to be exported to IFC, it has to have
an object classification assigned. To look at the default styles go to
ProgramData\Autodesk\MEP 2013\enu\Styles directory and open the IfcShareBldgElements (MEP).dwg file.

In
the style manager, look at the classification definitions under Multi-purpose objects. IFC properties
can be assigned to these objects:

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Once the items are selected, the classifications tab lists the information associated with an MEP
object that will be exported:

To use these in a file, and assign them to MEP objects, you
have to copy them into your current drawing. Use copy and paste in the style manager to add both classification
definitions to the current drawing.

Select OK to exit
the style manager. Now that they’re in the drawing, you can edit the properties
of objects to assign the classification. I’ll grab the ductwork, and then go to
the properties palette:

For most other parts, IFC
Type Classifications are mapped to MvPart
Objects (such as equipment, panels, and devices) automatically. This
classification is added in the Autodesk Catalog Editor by default. You can
modify this classification or add more classifications to the content library
in the Autodesk Catalog Editor.

Once
you’ve added the correct classifications to MEP objects, review the IFC export settings. From the
application menu, select the Export
tool, and then select IFC. The
options are located on the export dialog, and the object tab lists all objects that loaded into a drawing
– you can choose to add or remove objects as needed.

After you review the options, you can run the export. The
IFC file is created in the project folder. To test this, I’m going to open the
file in Revit. Before doing this, open the IFC
Import options on the Application
menu, under Open:

Before importing an IFC file, you need to go through and map IFC class names to Categories and sub-categories. This tells the MEP object what is used to control
its display in Revit.

Once the IFC file is imported, it will appear something like
this:

The imported objects take on most of the characteristics of
the equivalent objects in Revit. You may need to check IFC mappings in both the
AutoCAD MEP file and the Revit file during this process, but this represents a
major leap in compatibility between the applications.

Be aware that imported objects may not completely take on
the behavior of a normal duct. For example, the duct is treat like a duct with
properties assigned, but it does not include the connection, system or sizing
behavior. You have to add a connector to attach duct to it.

1 comment:

I have an issue related to this workflow. Hopefully I can pose the question in a manner that's easy to understand....When assigned property set definitions to an MVpart in AutocadMEP, a list of Psets come up based on type classification. How do I know which of these property set definitions pertain specically to the part? An example would be a diffuse. When I try to assign the tables, indeed the list comes up, with diffuser being one of the tables, but I also get others that dont seem closely relational.

About Me

I'm the BIM Specialist for the engineering team at Gannett Fleming, a large engineering firm based in Camp Hill, PA. My expertise is based on over 29 years of architectural and MEP engineering design and CAD management experience. I have an Associate of Applied Science in Architecture from Wake Technical College. My Autodesk product specialties are in Autocad MEP/Building Systems and AutoCAD Architecture/Architectural Desktop, Revit Architecture and Revit MEP, Ecotect Analysis and Virtual Environment VE-Pro. I am also proficient with Naviswork, Plant 3D and am working on getting up to speed on Bentley BIM as well.
My certifications include Autodesk Expert Elite, Autodesk Architectural Desktop Certified Expert, AutoCAD/Revit MEP Implementation Certified Expert and an Revit Architecture 2015 Certified Professional. I enjoy teaching at Autodesk University every year as well. Previously, I worked in the Autodesk reseller channel from 1997-2010.